LOS ANGELES CA (RPRN) 05/14/09 -- Megan Fox recently admitted during an interview with Esquire, "I have no question in my mind about being bisexual ... I mean, I could see myself in a relationship with a girl -- Olivia Wilde is so sexy she makes me want to strangle a mountain ox with my bare hands."

Adding her to the celebrity hot list of women that identify as bisexual, including Angelina Jolie, Madonna, and on some days, Drew Barrymore, one can’t help but wonder whether bisexuality is a trend, a choice or something more real altogether, like its own identity.

According to Newsweek’s culturally definitive cover on bisexuality in the mid-nineties, “Bisexuality is the hidden wild card of our erotic culture. It is what disappears when we divide desire into gay and straight, just as millions of Americans of various ethnic origin disappear when we discuss race in terms of black and white. Now, in scattered pockets, bisexuality is starting to become more visible.”

For over two centuries, scientists have documented sexual attraction to both sexes in men and women and argued its place in the evolution of sexual identity. Some analysts, like Freud, asserted that humans are naturally bisexual. In his landmark sex surveys of the 1940s, Dr. Alfred Kinsey discovered many married, publicly heterosexual men who reported having had sex with other men.

"Males do not represent two discrete populations, heterosexual and homosexual," Dr. Kinsey wrote. "The world is not to be divided into sheep and goats."

However, we’ve all been privy to the “bisexuality” that flits in during a drunken evening at a keg party and that flash in the pan is hardly what researchers care about. Plus, it usually involves two women.

A case in and of itself that seems to be a wild card compared to studies done on men.

According to new research by the American Psychological Association that tracked 79 non-heterosexual women for a decade, bisexual women continue to be attracted to both sexes over time.

“Being bisexual is a distinct orientation, not a temporary stage,” says the study by Lisa Diamond, an associate professor of psychology and gender studies at the University of Utah. Her study was published in early 2008 in Developmental Psychology, a journal of the American Psychological Association.

Are these women pursuing active relationships with other women? And what is the societal impact of bisexual women carrying on partnerships with other females?

"If it was a phase, it should have burnt out," Diamond says. "They might have a change in identity and relationships, but that pattern of non-exclusive desire is still there, even among those who have married. It debunks the notion of it being a phase."

Diamond suggests that most women "possess the capacity to experience sexual desires for both sexes, under the right circumstances." Whether those circumstances include alcohol is unclear.
Diamond says heterosexual women may "experiment with same-sex desires and behaviors, but if they really are predominantly heterosexual, they may enjoy experimentation but may not change their sexuality."

The study also zeroes out the stereotype that bisexual women aren't able to commit to monogamous relationships because they're always thinking about desire for the other gender.

On the other hand, a very different result was encountered after a study on 101 men who claimed to be bisexual. According to the New York Times, “In the experiment, psychologists at Northwestern University and the Center for Addiction and Mental Health in Toronto used advertisements in gay and alternative newspapers to recruit 101 young adult men. Thirty-three of the men identified themselves as bisexual, 30 as straight and 38 as homosexual.
The researchers asked the men about their sexual desires and rated them on a scale from 0 to 6 on sexual orientation, with 0 to 1 indicating heterosexuality, and 5 to 6 indicating homosexuality. Bisexuality was measured by scores in the middle range.”

"Regardless of whether the men were gay, straight or bisexual, they showed about four times more arousal" to one sex or the other, said Gerulf Rieger, a graduate psychology student at Northwestern and the study's lead author.

"I'm not denying that bisexual behavior exists," said Dr. J. Michael Bailey, a professor of psychology at Northwestern and the new study's senior author. "But I am saying that in men there's no hint that true bisexual arousal exists, and that for men arousal is orientation."

However, focusing only on arousal and not the other, more emotional and intimate factors involved in attraction could be the issue here.

“Social and emotional attraction are very important elements in bisexual attraction,” said Dr. Fritz Klein, a sex researcher and the author of "The Bisexual Option."

While some scientists race to the conclusion that not enough research has been done to eradicate the existence of bisexuality based on this test, one must investigate why anybody would try to erase an entire identity based on a test and a test that includes only one sex?

"Research on sexual orientation has been based almost entirely on self-reports, and this is one of the few good studies using physiological measures," said Dr. Lisa Diamond, who was not involved in the study.

Denise Penn, a clinical social worker who serves on the board of the American Institute of Bisexuality, based in San Diego, says “Women's sexuality in general has taken a back seat in terms of research overall."

"There's a whole lot of movement and flexibility," Dr. Diamond added. "The fact is, we have very little research in this area, and a lot to learn."

If you find yourself questioning your own sexual identity, you can always indulge in the online quiz, “You’re Probably Bisexual If…” But obviously... there are no guarantees.